Snap-in flange seal and locator

ABSTRACT

An annular seal is placed between the flanges of two pipes or conduits to seal against high pressure or vacuum. A flat inner ring has the inside diameter of the pipe and is formed on its outer edge with a truncated V groove. A flat outer ring has an inside diameter slightly greater than the outside diameter of the inner ring and its inner edge is also formed with a truncated V groove. A circular cross-section O ring is received in the two grooves, its unstressed diameter being greater than the thickness of the flat rings so that when the seal is placed between two flanges the O ring flexes to partially fill the grooves and to seal against both flanges. To locate the annular seal accurately a thin locating ring surrounds the annular seal and is detachably secured thereto by lugs which fit into a groove in the external edge of the outer flat ring. The locating ring has a pair of opposed ears which are slotted or otherwise apertured to receive the bolts which draw the pipe flanges together. Since the flanges and bolt hole circles may be of varying diameters depending upon the designed pressure for pipes of the same nominal inside diameter, the slots or apertures are shaped to center the seal for several different size flanges.

This invention relates to a new and improved snap-in flange seal andsnap-in locator. More particularly, the invention relates to an annularseal to fit between the flanges of high pressure or high vacuum pipes toseal the same. The annular seal has an inner ring and an outer ring withan O ring interposed and fitting partiallly within truncated V-shapednotches in the opposed edges of the two rings. When the flanges aredrawn together, the O ring is deformed and partially fills the truncatedV-shaped notches. A tight seal of the edges of the O ring against bothflanges is achieved. In order to locate the annular seal accuratelyrelative to the central axis of the pipe, the annular seal may besnapped into a locator which fits around the outside thereof and can beused to center the assembly relative either to the bolt holes in theflanges or the external edge of the flanges.

Accordingly, a principal purpose of the present invention is theprovision of a means which may be used with an annular seal to locatesuch seal relative to the central axis of the pipe. Thus the accuracy oflocation and the elimination of the possibility that the seal projectsinto the pipe opening is eliminated; and further, the O ring of theannular seal is accurately centered relative to the central axis of thepipe.

Another feature of the invention is the fact that the bolt holes and thebolts which are used to draw the flanges together function incooperation with the locator to center the assembly. It will beunderstood, that for different pipe pressures the size of the flange,the bolt circle on which the bolts are located and the size of the boltsthemselves vary. The locator of the present invention accommodatesdifferent flange sizes, bolt circles and bolt diameters.

A second means which is incorporated in the locator is a series ofarcuate scribe marks on a projecting ear of the locator which areconcentric with the pipe axis and line up with the outside diameter ofthe flange. Thus the workman may hold a tab on a projecting ear of thelocator and line up a scribe mark with the outside edge of the flangeand be assured that the seal is accurately centered. A further featureof the invention is the fact that the tab is weakened in notches so thatit can be torn off by the workman after the flanges have been drawntogether by tightening the flange bolts.

Another feature of the invention is that the locator and the annularseal are preferably separable and can be snapped together. Thusdifferent types of seals for different fluids in the pipe (e.g.) ordifferent makes of seals may be used with a uniform locator.

Another feature of the invention relates to the shape of the grooves inthe opposed surfaces of the inner and outer rings of the annular seal.Heretofore V-shaped grooves have been used in conjunction with O rings.However, the grooves of the present invention are truncated. Hence therelative volumes of the two grooves in relation to the volume of the Oring is more carefully controlled and the effectiveness of the seal ofthe distorted O ring against the flanges is likewise more carefullycontrolled.

Other objects of the present invention will become apparent upon readingthe following specification and referring to the accompanying drawingsin which similar characters of reference represent corresponding partsin each of the several views.

In the drawings:

FIG. 1 is a somewhat schematic partial sectional view through theflanges of two pipes showing the seal and locator of the presentinvention in place.

FIG. 2 is an elevational view showing the seal and locator in placerelative to a small diameter flange for relatively low pressure pipes.

FIG. 3 is a view similar to FIG. 2 showing the locator in place againstthe flange of a larger size for higher pressure pipe.

FIG. 4 is a fragmentary sectional view through the edge of one of therings of the seal.

FIG. 5. is an enlarged fragmentary plan view of a portion of one of theears of the locator and its detachable tab.

Typical high pressure or high vacuum pipes 11 have hubs 12 welded orotherwise attached thereto with flanges 13 extending therefrom. In theform of flange 13 shown in FIG. 1, steps 14 are formed in the innerfaces of the flanges to insure that when the flanges are tightened theseal will seat properly. Holes 16 are formed adjacent the outer edges ofthe flanges 13 and the opposed flanges are drawn together by bolts 17 orother conventional means well understood in this art. By comparison ofFIGS. 2 and 3, it will be seen that for different pipe pressures,although the inside diameter of pipe 11 remains the same, the outsidediameter of flange 13 or 13a may vary and the radius of the circle onwhich the holes 16 or 16a are formed may likewise vary. The number ofbolts 17 and the diameter of the bolts 17 and hence the diameter of theholes 16 or 16a is also subject to variation. These variations arecontrolled by standards adopted by governmental codes or engineeringsocieties. It is an important feature of the present invention thatdifferent flanges are accommodated.

In order to seal the two flanges 13 against pressure or vacuum, anannular seal 21 is employed. Seal 21 has an inner ring 22 formed of thinmetal or plastic having an inside diameter 23 which is no less than thediameter of pipe 11 and preferably is equal to the inside diameter ofhub 12. The ring 22 is flat and thin and of a thickness of about 1/8inch. A groove 24 is formed on the outside edge of ring 22. As shown inFIG. 4, groove 24 is of a truncated V shape. The sides 26 thereof slantinwardly at an angle of about 15° relative to the top and bottom facesof ring 22. The bottom 27 of the groove is parallel to the axis of thering. The outer edges 28 of the ring are very thin, being about 0.010.The depth of the groove is about 0.0835. In a preferred form of theinvention the annular ring 22 has a thickness of about 1/8 inch and isformed of epoxy-glass fabric, Nema type G-10.

Surrounding ring 22 is outer annular ring 31 which is formed of similarmaterial and is of similar thickness. Ring 31 is formed with a groove 32in its inside edge which is complementary to groove 24. Fittingpartially within the grooves 24 and 32 is an O ring 36 which in itsunstressed condition is of a diameter considerably greater than thethickness of the rings 32, 31. When the flanges 13 are brought together,the ring 36 deforms and partially fills the grooves 24, 32.

The ring 31 is formed with a groove 33 on its outer edge which may besimilar to the groove 32. Locator 41 comprises a ring of thin plasticmaterial such as polyethylene which has an inside diameter 42 slightlygreater than the outside diameter of ring 31 and is also formed witharcuately spaced lugs 43 on the inside diameter which snap into thegroove 33 by reason of the resilient nature of the locator 41. Extendingradially from locator 41 is a first ear 46 which is formed with a radialslot 47 extending inward from the outer edge of ear 46. The inner wallof slot 47 is formed with an inner radius 48. Outwardly of radius 48 areslanted sides 49. Directing attention to FIGS. 2 and 3, for a smalldiameter bolt hole 16, as shown in FIG. 2, the radius 28 is tangentthereto. As shown in FIG. 3, the slanted sides 49 are tangent to thelarge bolt holes 16a. Thus a single locator 41 will serve to locaterelative to a plurality of different flanges 13 or 13a having differentbolt circles and different bolt hole diameters.

Diametrically opposed to first ear 46 is second ear 51. Although thesecond ear 51 may be identical to the ear 46, in a preferred form of theinvention, as best shown in FIG. 5, it is formed with a keyhole shapedaperture 52. The inner radius 53 of aperture 52 is similar to the radius48 of ear 46. Parallel sides 55 of the aperture 52 connecting with theouter radius portion 54 is of a diameter such that it accommodates thesame bolt hole 16a as the slanted sides 49 of first ear 46, 49.Extending outward beyond radius 54 is a tab 56. Notches 57 are cut intothe ear 51 about at the widest part of aperture 52 and these notchesenable the tab 56 to be snapped off after the flanges have been drawntight. Thus the workman holds onto the tab 56 and can move the locator41 and also the seal 21 which is held thereby so that the assembly isaccurately centered and then break off the tab 56 at the notches 57. Analternate means of using the locator 51 is the use of scribed arcs 59which are either cut into or embossed on the tabs 51. For differentpressures (as indicated by legends near the scribe marks 59) differentoutside diameter flanges 13, 13a are required. The scribed arcs 59 areused by the workman to line up with the outside edge of the flange. Thenthe bolts 17 are tightened and the tabs 56 broken off. Instead ofscribed arcs 59, silk-screened or printed on embossed markings may beused. Legends 61 (as shown in FIG. 5) may be applied near the marks 59.

Accordingly, the present invention accommodates different line pressuresor vacuums and the seal therefor is accurately centered relative to theaxis of the pipes. Because of pressure variations the design of theflanges of the hubs of the pipes vary but the centering deviceaccommodates wide variations.

Accordingly in use, the proper seal 21 is selected. The proper O ring 36is installed between the inner and outer rings 22, 31, portions fittinginto the grooves 24, 32. The seal is installed between flanges 13. Thetab 46 or 51 is used in one of several ways. If the bolts 16 are in asmall radius bolt circle, the surface 48 is placed so that it is tangentto the inside of one of the circles 16. Thereupon, the bolts areinserted through the flanges and drawn tight. Alternatively, if the boltholes 16a are at a greater radius and the diameters of the holes 16a isgreater than the diameter of the holes 16, said tab 46 or 51 is moved sothat the surfaces 49 are tangent to a hole 16a and the procedure ofjoining the flanges is repeated. As a third alternative, the tab 56 isgrasped and the portions of the holes 52 are brought into tangency withthe holes 16 or 16a as in the preceding modification, the flanges drawntight by means of the bolts 17 and the tab 56 broken off at the notches57. As a final alternative, the tab 56 may be gripped and the lines 59brought into a position so that they coincide with the outside diameterof the flange 13.

What is claimed is:
 1. A seal to be interposed between the two flangesof the abutting pipes or conduits, said flanges each having a pluralityof bolt holes arranged in one of at least two plurality of bolt circlesof different radii, said seal comprising a seal proper having means toform a tight pressure differential seal against both said flanges whensaid flanges are drawn together by tightening bolts through aligned boltholes, said seal proper having an inside diameter no less than theinside diameter of said pipes or conduits, and a locating ring engagingthe outside edge of said seal proper, said locating ring formed with aradially projecting ear, said ear formed with an opening which has anarrower portion near said seal proper and wider portion farther fromsaid seal proper, said narrower portion being tangent to a first bolthole on the smaller of said bolt hole circle, said wider portion beingtangent to a second bolt hole on the larger of said bolt hole circles,whereby said seal proper may be located concentric with the pipe orconduit by moving said ear so that it is tangent to the proper bolt holeof one of said flanges.
 2. A seal according to claim 1 in which saidlocating ring is formed with a second projecting ear opposite saidfirst-mentioned ear, said second ear formed with an opening having asecond opening which has a second wider portion and a second narrowerportion, said second narrower portion being tangent to a third bolt holeon the same circle as said first hole, said second wider portion beingtangent to a fourth bolt hole on the same circle as said second hole. 3.A seal according to claim 2 in which said second opening is a notchextending inward from the outer edge of said second ear.
 4. A sealaccording to claim 2 in which said first-mentioned opening is akeyhole-shaped hole.
 5. A seal according to claim 4 in which saidfirst-mentioned ear is weakened at the widest portion of saidkeyhole-shaped hole to provide a tab capable of being torn off wheresaid ear is weakened.
 6. A seal according to claim 5 in which said tabis formed with a series of markings at different distances from thecenter of said seal proper whereby the outside diameter of one of saidflanges may be lined up with one of said markings to center said sealrelative to said pipe or conduit.
 7. A seal according to claim 1 inwhich said locating ring is capable of being attached to and detachedfrom said seal proper.
 8. A seal according to claim 7 in which the outeredge of said seal proper is grooved and said locating ring is formedannular with inward projecting lugs to snap into the groove in saidouter edge.
 9. A seal according to claim 1 in which said seal propercomprises an annular inner ring, a larger annular outer ring and anO-ring between said annular rings of substantially greater thicknessthan said annular rings and said locating ring.
 10. A seal according toclaim 9 in which the opposed edges of each of said annular rings isgrooved and said O ring is partially in the grooves of each of thegrooves in said annular rings.
 11. A seal according to claim 10 in whicheach of said grooves is of truncated V cross-section.